The Sixth International Workshop on Langerhans Cells will be the next in a series of biennial meetings in which researchers studying cutaneous antigen presenting cells and related dendritic antigen presenting cells meet to exchange information, present their latest findings and, most importantly, use this interchange to develop new strategies for studying questions regarding the molecular biology, cellular biology and the immunologic role of these cells in normal physiology and pathophysiology. The role of dendritic cells as therapeutic agents will also be a topic within the meeting. The meeting will take place October 8-10, 1999 in New York City. Meeting participants will include experts invited to present plenary lectures on the latest developments in the field and students, research fellows, clinical physicians and scientists from academia and industry who will learn from the plenary lectures, present their latest findings in workshops and poster sessions and take part in formal and informal discussions and interchange of information. Indeed, the goals of this meeting are to provide a setting in which researchers in the field present their latest and most exciting work in the most interactive manner possible. Topics to be covered are: 1. The development and functions of Langerhans cells and other dendritic antigen presenting cells. 2. The role of Langerhans cells and dendritic cells in host defenses against malignancies and their use in vaccine strategies. 3. The role of Langerhans cells and dendritic cells in allergy, autoimmunity and induction of immunologic tolerance. 4. The role of Langerhans and dendritic cells as therapeutic agents for the treatment of disease. 5. The use of Langerhans cells and dendritic cells for molecular approaches to understanding dendritic cell development and physiology.